The proposed research investigates longitudinal determinants of distress among mothers of children undergoing bone marrow transplant (BMT) in the treatment of pediatric cancer. Data would be collected from up to 509 mothers during 5 structured interviews to occur at 2-weeks before BMT, immediately before BMT, and 6, 12, and 18 months post BMT. The proposed work would be guided by a conceptual integration of research in the areas of parental responses to BMT, cognitive/social processing of negative life events, and the impact of dispositional characteristics and prior stressful life events on adjustment to a severe negative life event. Stated aims are to 1) examine the longitudinal course of distress in the mothers of children undergoing BMT; 2) determine the role of cognitive and social processing in the development and maintenance of mothers' distress during and after BMT; and 3) assess how dispositional optimism, monitoring coping style, and prior negative life events influence mothers' cognitive and social processing of their distress after BMT. The proposed data analysis consists of latent growth curve and structural equation modeling.